Green Synthesis of Nanoparticles: Recent Advances and Environmental Applications

Abstract

Green synthesis of nanoparticles has emerged as a sustainable and eco-friendly alternative to the conventional physical and  chemical methods, which are associated with toxic reagents, high energy consumption and hazardous by-products. This  review focuses on the recent developments in the synthesis of nanoparticles using biological sources like plant extracts,  bacteria, fungi, algae, enzymes, biopolymers and waste materials, etc. These natural agents act as reducing, stabilizing and  capping agents and allow the formation of nanoparticles under mild and environmentally friendly conditions. The review  covers the main mechanisms such as metal ion reduction, nucleation, growth, stabilisation and capping, as well as the  influence of the reaction parameters on the properties of nanoparticles such as pH, temperature, reaction time, concentration  of the precursors and composition of the extracts. Different types of green synthesised nanoparticles, such as metal, metal  oxide, magnetic, carbon-based and hybrid nanoparticles, are picked for their relevance to the environment. The applications  in wastewater treatment, degradation of dyes, heavy metals, pharmaceutical and pesticide pollutants, antimicrobial  disinfection, soil remediation, air pollution control and environmental sensing are highlighted. Although they have great  potential, issues of reproducibility, toxicity testing, environmental fate, long-term stability, scale-up and life-cycle  evaluation remain important. In conclusion, green synthesis is a versatile and environmentally friendly approach to  nanotechnology that holds promise for sustainable production of nanomaterials and for addressing environmental  challenges such as pollution control, environmental remediation, and ecological protection.